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The graph between the resistive force F acting on a body and the distance covered by the body is shown is shown in the figure. The mass of the body is 60 kg and the initial velocity is 3m/s. When the distance covered by the body is 4m, its kinetic energy will be 

 

  • Option 1)

    250 J

  • Option 2)

    230 J

  • Option 3)

    200 J

  • Option 4)

    220 J

 

Answers (1)

best_answer

As we learnt in 

Kinetic energy -

k= \frac{1}{2}mv^{2}

- wherein

m\rightarrow mass

v\rightarrow velocity

kinetic Energy is never negative

 

 K=\frac{1}{2}mV^{2}=\frac{1}{2}\times60\times3^{2}=\frac{1}{2}\times60\times9

K=\frac{540}{2}=270 J

Work done against resistance force = Area between F-x graph  =\frac{1}{2}\times 4\times 20=40 J

\therefore    Final K.E. = 270 - 40 = 230 J


Option 1)

250 J

Incorrect

Option 2)

230 J

Correct

Option 3)

200 J

Incorrect

Option 4)

220 J

Incorrect

Posted by

Aadil

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